The present invention concerns a system for assembling the barrel of a medium or large calibre gun to a sleeve on the gun's breech block, the said system being of the type comprising a nut which is screwed on a threaded end of the barrel.
At present barrels are usually attached to the sleeve by means of one of two techniques. In one technique, the barrel is screwed into the breech block by means of matching threads made in the sleeve and on the barrel respectively. In practical terms this technique requires the barrel to be rotated, which is not a simple operation owing to its size and weight. Also, where it is required to obtain a given angular position between barrel and sleeve, the necessary thread starts have to be machined in a highly precise manner, which is also a delicate operation. In a second technique, the barrel is attached to the sleeve by means of a nut at the forward end of the sleeve, the threads in the said nut engaging with a thread on the sleeve. In this case, it is no longer necessary to rotate the barrel, but the presence of the nut at the forward end of the sleeve increases its size. However, the process of screwing the nut is still delicate owing to the tightening torque that has to be applied.